Who is Tiffany Trump?

All four of Donald Trump's adult children will speak at the Republican National Convention this week. Three of them have become familiar faces on the campaign trail. One remains a relative unknown.

Tiffany Trump, the youngest of the four, recently graduated from the University of Pennsylvania. Tuesday's speech will mark the 22-year-old's first major outing on the campaign trail -- and it will be in prime time, right after New Jersey Gov. Chris Christie.

Although Tiffany Trump isn’t a regular in front of the cable TV cameras, she’s already famous — or at least Internet famous, and that counts, right? The recent University of Pennsylvania graduate has an enviable 156,000 followers on Instagram who follow her adventures among the infinity pools and ski slopes that constitute the backdrop for her young-and-fabulous set.

A New York Times story recently dubbed Tiffany Trump’s gaggle of social-media savvy fellow children-of the the”Snap Pack”: the gang includes RFK Jr.’s daughter Kyra Kennedy, Stephanie Seymour’s son Peter Brant Jr., and Gaia Matisse, the great-great granddaughter of painter Henri Matisse.

To put her IG following in perspective, that’s a lot less than her father (with 1.9 million) but enough to qualify her, in the parlance of ‘gramming experts, as a“mid to top-tier influencer,” on par with the likes of minor reality TV stars.

She's the only child from Trump's second marriage, and grew up with her mother

Tiffany Trump's three older siblings are actually half-siblings, born to Trump's first wife, Ivana Trump. Tiffany is the daughter of Trump's second wife, Marla Maples. The mother of Trump's youngest child Barron is Melania Trump, the nominee's third wife.

Tiffany also grew up in California -- with her mother, to whom she's very close -- and not in New York with the rest of her siblings.

“I don’t know what it’s like to have a typical father figure,” she told Dujour. “He’s not the dad who’s going to take me to the beach and go swimming, but he’s such a motivational person.”

Maples has described herself as raising Tiffany Trump as a "single mother."